gatoman39

@helix:
Thank you for your concise answer.
Does APR switching involve some elaborate process or can it be done easily?

clochner

No pretty easy. Here's a video of the process on a VW: http://www.youtube.com/watch?v=XOEiFbSHKqk

rktskicar

I owned an APR EMCS ECU on my last S4 (B5) for many years. Very easy to switch programs. Just uses cruise control stalk to select which program. I also had an APR home programmer, so I could change what programs I had loaded in my ECU at will. The old EMCS system had a seperate piggyback board in ECU that had an RS-232 port so you could load in from your PC.

Bruce

helix139

I should also note that if you get the Stasis tune, Audi will know about it.

If you get the APR tune, the only way Audi will know about it is in the event of catastrophic failure if they choose to do a close inspection of the ECU programming, or if your dealership takes your car out and logs boost up to redline. Your dealership will not know you have the tune simply by plugging it into one of their diagnostic machines.

TM//S4

Here are a couple quotes from Tiffani @ Statsis - Dir of Sales:

When asked about the 91 octane issue: "It is optimized for 91, 93 or 100 based on fuel usage."...and... "Yes out ECU upgrade will produce more power based on the 91, 93 or 100 octane."

When aksed about sourcing through APR: "The Signature Series software is our own tune, designed in house."

helix139

Tiffani is wrong, and why would Stasis admit that? APR has strongly implied that they did Stasis' tune and has never denied it. When asked directly about it, they've said on more than one occasion something to the effect of APR being the only company that has cracked the B8 S4 ECU. Many who got the Stasis tune also reported their ECUs coming back to the dealership in APR boxes. It's the worst kept secret there is on these boards.

Their tune, like APR's 91 tune (because they are probably identical or Stasis is a slightly de-tuned APR 91 tune) will adapt to octane and provide more power when using 93 or 100 octane, but not as much as using a dedicated 93 or 100 octane tune.

NWS4Guy

Helix is 100% correct (on all parts)

rktskicar

This is only true if you do not have an APR EMCS ECU. If you have an APR EMCS ECU, switch it back to stock program before taking it for service. I did this for many years with my EMCS ECU on my B5 S4.

Bruce

helix139

True, but currently this is not a factor because there is no EMCS available for the B8 S4.

Even then, I would think that in the unlikely event of a catastrophic failure there would be a way to tell if Audi decided to pull the ECU and examine its contents thoroughly. Even then, legally they would have to prove the ECU caused the failure and APR would likely step up to the plate and go to bat for you to disprove any accusations coming from Audi.

That said, it's unlikely and they'd have to have a real reason to go beyond just checking the flash counter that APR resets.

Personally, I'll have no problems choosing APR when I decide to get my ECU flashed.

rktskicar

There will be one soon, though...

http://forums.quattroworld.com/s4b8/msgs/22952.phtml

I am waiting for this ECU. I do not want to pull my ECU twice.

Bruce